Unipivot

Unipivot refers to a bearing or support arrangement in which a moving element is mounted on a single point, rather than on two or more supports. The term is used in several disciplines, most notably in turntable tonearms and in certain precision instruments, to describe a low-friction, single-point pivot.

In turntable technology, a unipivot tonearm uses one bearing point at the base of the arm instead of a conventional two-point or knife-edge bearing. The pivot typically consists of a small jewel, ball, or hardened bearing seated in a housing that allows the arm to rotate with minimal friction. Proponents cite reduced friction and lower effective moving mass, which can enhance tracking sensitivity and musical response. However, the single-point design can be more sensitive to vertical tracking force, cartridge alignment, and external disturbances, making precise setup and damping more critical to avoid skating or mis-tracking.

Beyond audio, unipivot bearings have been used in some precision balances and laboratory instruments where a single contact point can minimize friction and wear. In these contexts, reliability depends on bearing quality, alignment, and protective measures against contamination.

Compared with bifurcated or knife-edge bearings, unipivot designs trade stability and ease of setup for potentially lower friction and inertia. They require careful manufacturing tolerances, stable mounting, and sometimes damping to maintain smooth, controlled motion.